Urgent, need opinions on my new crate engine

[geezer#99]

I think you're going in the wrong direction with your motor choice 1972Blue.
You were worried about your choice of the 290 hp motor and now you're jumping deeper into the fire with even more motor.
You've got a big tall tire heavy truck that needs all the torque you can find. Buying more hp moves the hp/torque curve way up the ladder. Right out of your desired driving area.
It'll be a dog until it hits 3000 rpm.
You need a stock motor with some upgrades. Like this one.
http://www.summitracing.com/int/sear...g&autoview=SKU
Add a high flow performer intake, a small 600 cfm carb, a set of small tube (1 5/8") headers and you'll be far happier.
You'll set the tune on your motor and only need to look at it to check the oil.
The high horse motor will need constant attention. You'll be continuously tweaking the carb, checking the timing etc.
Forget the bling bling high horse motors, go stock.
Unless you enjoy tinkering all the time!

[1972BlueC20]

So I'll be happier with a 195 hp 350 tq engine over a 330 hp 380 tq engine?

[geezer#99]

Maybe!!
Do you do your own wrenching or get a mechanic to do it?
Do you do your own timing or carb adjustments?
Do you normally drive above 3000 rpm?

[Lattimer]

Originally Posted by 1972BlueC20

Ok cool.

What's the temperature valve for?

Should I have one of these?

Thats what controls hot/cold on your heater. You should have one in the heater return hose

[1972BlueC20]

Originally Posted by geezer#99

Maybe!!
Do you do your own wrenching or get a mechanic to do it?
Do you do your own timing or carb adjustments?
Do you normally drive above 3000 rpm?

I'm having a mechanic install everything and get it all dialed in, but I do work on my truck. I can do most medium level jobs. My problem is lack of certain tools and space. I have more $$$ than time at this point in my life.

As for my driving, I drive pretty aggressive. Not drag racing from light to light, but pretty aggressive. Or I'll just cruise normally and I don't care about power till I floor it. Lol

I never haul or tow anything.

[Lattimer]

Originally Posted by geezer#99

I think you're going in the wrong direction with your motor choice 1972Blue.
You were worried about your choice of the 290 hp motor and now you're jumping deeper into the fire with even more motor.
You've got a big tall tire heavy truck that needs all the torque you can find. Buying more hp moves the hp/torque curve way up the ladder. Right out of your desired driving area.
It'll be a dog until it hits 3000 rpm.
You need a stock motor with some upgrades. Like this one.
http://www.summitracing.com/int/sear...g&autoview=SKU
Add a high flow performer intake, a small 600 cfm carb, a set of small tube (1 5/8") headers and you'll be far happier.
You'll set the tune on your motor and only need to look at it to check the oil.
The high horse motor will need constant attention. You'll be continuously tweaking the carb, checking the timing etc.
Forget the bling bling high horse motors, go stock.
Unless you enjoy tinkering all the time!

Actually, the vortec head engines make begin making torque pretty low, and have a broad flat curve if done correctly.

Stock is NEVER a good answer to anything.....LOL

[1972BlueC20]

Originally Posted by Lattimer

Actually, the vortec head engines make begin making torque pretty low, and have a broad flat curve if done correctly.

Stock is NEVER a good answer to anything.....LOL

That's what my mechanic said. I asked him about just buying the cheap engine and he said why go through all this $$$ and trouble just to get a stock engine.

Keep in mind, he doesn't make any more money on the install regardless of whether I buy the vortec engine or the base engine.

[turp mcspray]

The 290hp engine is just a mismatched mess!
At 2500 rpm, the 290hp engine has about 280lbs of torque, and the 330hp engine has about 350lbs. 70 lbs is a LOT, and you WILL notice it!

[1972BlueC20]

Originally Posted by turp mcspray

The 290hp engine is just a mismatched mess!
At 2500 rpm, the 290hp engine has about 280lbs of torque, and the 330hp engine has about 350lbs. 70 lbs is a LOT, and you WILL notice it!

That's what I figured.

[mechanicalman]

Originally Posted by Lattimer

Definitely a better engine, 1 piece rear main is a vast improvement. It will require a different flywheel and balancer than the other engine. Also different manifold. Very similar to what I am running. I just have the vortec heads with the bigger valves.

It's called an "external" balanced engine because it's a 1pc rear main seal, so a 2pc rear main seal crankshaft has a balance weight hanging off the end and they removed that to facilitate using a 1pc seal thus a counter-weighted flywheel.

The front of the engine is not affected and takes a regular balancer.

Production Vortec 350's (L31's) take a shorter balancer due to crank sensor, those are the ones with plastic timing covers and reluctor wheel between the lower timing gear and the balancer.

[Lattimer]

Originally Posted by mechanicalman

It's called an "external" balanced engine because it's a 1pc rear main seal, so a 2pc rear main seal crankshaft has a balance weight hanging off the end and they removed that to facilitate using a 1pc seal thus a counter-weighted flywheel.

The front of the engine is not affected and takes a regular balancer.

Production Vortec 350's (L31's) take a shorter balancer due to crank sensor, those are the ones with plastic timing covers and reluctor wheel between the lower timing gear and the balancer.

Whoops! Misspoke on the balancer. Thanks for the correction.

[mechanicalman]

Originally Posted by 1972BlueC20

So this one should be a good noticeable improvement power wise over my stock engine and will be ok for the my larger GVWR of 6700-7500 ?

What balancer would it take and what flywheel? I think I know but you guys are always better at this stuff than me at this point in my knowledge level

You are going to LOVE this engine, I have one in one of my pickups. Great choice for an engine, and yes very noticeable power improvement over your stock engine.

You don't need a special balancer, but I would get a new one. I think you already got this one, right? Perfect.
http://www.summitracing.com/parts/su.../applications/
It will fit. Just make sure you use the correct indicator
http://www.summitracing.com/parts/su...make/chevrolet

You do need a special flywheel AND flywheel bolts to fit that engine. It's NOT the same as a 383 or 400, it's the same flywheel that chevy has used since they started 1pc rear main seals starting in 86. Again, there is a 153 and 168 tooth I'd get whatever one matches the starter you already got. The difference is the 153 will crank your engine faster, but not harder. The 168 will crank your engine harder, but slower.

This one will do you for a 168 tooth slow cranker
http://www.summitracing.com/parts/pi...make/chevrolet

This one will do you for a 153 tooth fast cranker
http://www.summitracing.com/parts/pi...make/chevrolet

Flexplate bolts
http://www.summitracing.com/parts/nal-14088764

You know you need a new Vortec style intake, right? You have an Edelbrock square bore AFB style carb, right?
The Best, $250.00
http://www.summitracing.com/parts/ed...make/chevrolet
Cheaper
http://www.ebay.com/itm/SBC-SMALL-BL...26b88c&vxp=mtr
Intake gaskets, get these they fit, do not split, last a long time.
http://www.summitracing.com/parts/na.../applications/
And, of course, special intake manifold bolts, sold individually, you will need 8.
http://www.summitracing.com/parts/na...0027/overview/

[RUN GMC]

Originally Posted by Lee H

Just for reference, My 72 C10, short fleet, 350/350, PS, PB, AC, spare, half tank of gas came in at 3,710 on a fresh fame off restoration. My 65 Corvette roadster came in at 3,146. Couple of fat chicks difference.

Nope he just likes them really really fat..................

[mechanicalman]

Originally Posted by Lattimer

Actually, the vortec head engines make begin making torque pretty low, and have a broad flat curve if done correctly.

Stock is NEVER a good answer to anything.....LOL

X2!

[Vintage Windmills]

Originally Posted by litew8

You can't go wrong with more HP. .

Except when lowend torque has been compromised for more high end horsepower.

[1972BlueC20]

Originally Posted by Lattimer

Thats what controls hot/cold on your heater. You should have one in the heater return hose

I don't have any kind of heater temp valve. The lines are just straight from intake to core, and from core to waterpump.

[1972BlueC20]

Thanks guys for all your input!

I think I'm going to send a lot of my parts back along with the 290 hp engine since they are paying for all the return shipping.

I'm going to just get this complete package. It's more of a turn key almost deal.


My phone won't post link right now Arggg

Gm part # 19210008

[Vintage Windmills]

Originally Posted by 1972BlueC20

I don't have any kind of heater temp valve. The lines are just straight from intake to core, and from core to waterpump.

That is the way these trucks are. Heat is modulated by a flapper that diverts air either through or around the heater core (in the fiberglass box mounted to firewall.) Not sure if burbs are different or why Lattimer has a different setup.

[mechanicalman]

Originally Posted by 1972BlueC20

I don't have any kind of heater temp valve. The lines are just straight from intake to core, and from core to waterpump.

If your truck does not have a/c, then that is normal. If it has a/c, there should be a vacuum switch on the a/c control head that has 2 nipples on it don't think it makes any difference which one goes where just one from manifold vacuum in and one out through the firewall to the heater valve on the R fenderwell.

IMPORTANT

That engine needs a thermostat by-pass hose. PLEASE don't let ANYONE talk you into drilling holes in the thermostat, this makes your engine take longer to warm up. Bypass hose will NOT make the engine take longer to warm up as it goes back to the water pump (not cooled by the radiator) or the cold side of the radiator ready to be sucked into the water pump.

IF you DON'T have a/c, and you DON'T install a heater valve and you DO keep coolant circulating from the top of the intake into either the water pump or the cold side of the radiator, then the heater circuit will function as a by-pass hose. CAUTION if your heater starts leaking, you by-pass it and forget about it then you could damage your engine. I would not do that with my forgetfulness.

IF YOU DON'T have any thermostat by-pass, eventually air/steam pockets will form before the thermostat opens and the thermostat will not see hot water to make it open, the engine will get hotter and hotter and you will eventually either blow hoses, heater core, radiator, and worse yet crack the heads. Here is an example of a vortec style engine with a by-pass hose, but it's a Ramjet 350 and that manifold has a fitting on the front for the heater supply.

For NON-a/c, heater supply you need what you probably already have a "restricted" 5/8" fitting.
http://www.napaonline.com/Catalog/Ca...515_0421632233
Shown is a short water pump, the fitting on the top for t-stat bypass and the fitting on the side for heater return. The heater return can also go to the nipple you will sometimes see on the cold (passenger) side of the radiator.

Another problem: For your temperature warning system, gauge or idiot light, your sensor or sender may be too large (1/2"NPT) to screw into the smaller hole on the Vortec head (3/8"NPT). However, the intake on your new engine might have the right passages to accommodate everything. The upper one on the passenger side for your heater fitting, the one on the upper driver's side for your temperature warning sender or sensor, and the one in the front for your thermostat by-pass hose. The bypass hose can be 5/8", you will have to remove the plug atop the water pump and adapt down to the proper size fitting for the hose you choose, or drill a hole in the plug and pipe tap it to the size you need.
https://www.google.com/search?q=3/8%...IQsAQ&dpr=0.95
https://www.google.com/search?q=3/8%...+5%2F8%22+hose
https://www.google.com/search?q=3/8%...+5%2F8%22+hose
https://www.google.com/search?q=3/8%...+5%2F8%22+hose
Lots of these can be found at Home Depot, Help sections at auto parts stores, or online, but I expect your mechanic will figure it out. If he (your mechanic) balks and wants to drill your t-stat, I'd round up the fittings myself and go to the parts store and get a pre-formed section of heater hose and cut it to fit. He's going to be in a hurry, and really don't get paid to run around and hunt parts.

IF the hole in the driver's side top of the intake is not 1/2"NPT but instead 3/8"NPT (hard to be sure just looking at the picture) you can use a different sensor and either put it there or leave it in the head. I think leaving it in the head looks better, but a better sample of pre-thermostat temperature on the intake, but might poke into the radiator hose. Splitting hairs LOL.

For 3/8"NPT Idiot light use Duralast TU81.
For 3/8"NPT Gauge sender use Duralast TU66.

You may have to install a female spade connector but it will probably shove on there. When your engine arrives, look over the intake/heads, check the water pump plug, sensor/sender on your old engine, and get your parts lined up coming so the installation can proceed un-hindered. Of course have it delivered directly to the shop installing it.

[mechanicalman]

Originally Posted by Vintage Windmills

That is the way these trucks are. Heat is modulated by a flapper that diverts air either through or around the heater core (in the fiberglass box mounted to firewall.) Not sure if burbs are different or why Lattimer has a different setup.

My 72 factory a/c came with a heater water valve, my 68 factory a/c did not.

I notice your 67 has a/c, but you don't show it on your newer trucks. I'd be interested to know just when they started putting it on.

72 is C10, 68 is C20.

[Lattimer]

Originally Posted by 1972BlueC20

I don't have any kind of heater temp valve. The lines are just straight from intake to core, and from core to waterpump.

Dunno.

My truck was non ac and had a cable operated valve in the heater hose line. I tore all of that out and put in aftermarket air, but it uses basically the same water valve.

[t5noel]

I bought the 195 HP 350 crate engine along with the summit TH350 rebuilt transmission a year or so ago. I put them in a 1974 GMC stepside 1/2 ton long bed. I am very happy with both to date. It has headers with a quadrajet carb and an Edelbrock 2701 Performer Intake Manifold. I have to be easy on the gas peddle, It wants to jump down the road.

[71K20chevy]

Fast. Cheap. Reliable. Pick two.

[1972BlueC20]

Originally Posted by 71K20chevy

Fast. Cheap. Reliable. Pick two.

Well said man!

[sprint_9]

Good choice on the engine, while it is more expensive now I think it will be a better piece for you in the long run. The 1 piece rear main and vortec heads are worth it.